The present invention relates in general to combination locks, and more particularly to spindles for combination locks that may be easily adapted for use under various mounting conditions.
Combination locks of the multiple tumbler wheel type with which the present invention is concerned usually comprise three disk-shaped tumbler wheels having a gating or notch in their periphery and spaced side-by-side on a cylindrical tumbler post projecting inwardly of the lock housing. One of the tumblers, either the forwardmost or rearmost of the three, typically is driven by a drive pin projecting toward the tumbler from a rotatable driving cam which directly engages a stop on the tumbler or a rotary fly washer which in turn engages such a tumbler stop to provide a lost motion driving connection. The remaining tumblers are driven by an adjacent tumbler in the direction of the driving cam through a similar lost motion driving connection. The driving cam has a generally cylindrical periphery interrupted by a gating shaped to receive a fence lever nose therein at one angular position of the driving cam. The gating is structured to permit the fence carried by the fence lever to approach the tumbler wheels and enter the tumbler gatings when they are aligned with the fence. Thereupon, rotation of the driving cam through a limited arc in a selected direction effects withdrawal of the lock bolt to which the fence lever is pivoted, as a result of the fence lever nose being seated in the driving cam gate.
The driving cam is rotated to position the tumblers and retract or project the bolt by keying it on a drive spindle projecting externally of the lock casing. A mechanical dial is fixed to the external end of the spindle. A typical prior art spindle is usually threaded over a substantial portion of its length, and the driving cam is generally designed with an internally threaded bore structured to be threaded onto the spindle. Both the spindle and driving cam are provided with a spline or keyway and are disposed to be in registry with each other when the driving cam gate is oriented in a preselected relation to the dial markings to receive a spline key and lock the driving cam and spindle against relative rotation. This rotation of the mechanical dial directly rotates the driving cam to effect adjustment of the tumblers and movement of the bolt.
It has been the customary practice in the lock manufacturing industry to locate the mating splines in the spindle and driving cam so that the driving cam may be keyed to the spindle at an angular position wherein the driving cam gating is located immediately below the fence lever nose to receive the nose when the zero dial marking, or a dial marking located no more than about ten points to the left or right of zero, is aligned with the fixed index mark for the dial readings. This practice has been adhered to largely because the dialing conventions for combination locks are such that the dial is usually rotated through three full revolutions in one direction to align the first number of the combination with the fixed index mark, then two full revolutions in the opposite direction to align the second number of the combination with the index mark, then one full revolution in the first direction to align the third number of the combination with the index mark, and then returned to zero and rotated through a preselected small arc to drop the fence lever nose into the driving cam gating, thus retracting the bolt. It is only by keying the driving cam to the spindle at such an angular position that the driving cam gate is positioned to receive the fence lever nose at or near the zero dial position. Thus, prior art spindles required that the manufacturer locate the spline in the spindle at the proper angular position to provide the required angular relationship between the driving cam and dial markings so that the driving cam gate may receive the fence lever nose when the dial is positioned near zero.
This type of spindle design would generally present no particular problem for manufacturers as long as the lock device coupled to the spindle was always installed at the same angular position relative to the dial. However, in actual practice, combination locks are installed in a wide variety of angular positions, termed “hands of installation,” depending upon the particular mounting application of the lock. For example, a lock device with a bolt projecting from one end thereof may be arranged in a right hand horizontal installation or a left hand horizontal installation, wherein the bolt projects to the right or to the left, respectively (when viewing the lock device from the rear). Right and left hand horizontal installations allow the lock device to be used with right or left hand swinging doors of safes or other secured areas. In other applications, such as for sliding drawers of filing cabinets, desks, and the like, and in some safe applications, it is desirable to arrange the lock device so that the bolt projects vertically up or down.
Each of these different hands of installation requires that either the spindle or the driving cam spline be located at a different angular position in order to preserve the relationship between the driving cam gate and the zero mark on the dial whereby the fence lever nose can drop into the driving cam gate at a dial position wherein a dial marking near the zero mark is aligned with the fixed index mark located vertically above the center axis of the dial. In order to accommodate the various installation conditions, the commercial locksmith must carry in his stock of repair parts spindles or driving cams keyed for each of the different hands of installation. The general practice for some locksmiths has been to stock spindles splined for each of the four principal hands of installation, including right horizontal, left horizontal, vertical up, and vertical down. However, having to stock a wide variety of spindles is not only inconvenient, but it also presents a substantial financial hardship to the locksmith.
In addition, the length of the spindles used in combination locks is not standardized and depends upon, for example, the separation distance between the dial on one side of the mounting surface and the lock on an opposing side of the mounting surface. For example, in some lock assemblies the required length of the spindle may be about two inches, while in other assemblies it may be about four inches. This factor also increases the variety and quantity of replacement parts which a locksmith must stock and carry in order to be adequately prepared for the variety of replacement possibilities which he may encounter. In some situations the locksmith may cut off a portion of the spindle in order to obtain a spindle having a desired length. However, under such circumstances, the portion of the spindle where the cut is made has to be “deburred” such that all sharp, jagged edges or other abnormalities resulting from the cut are eliminated. If this step is not taken, the spindle may, for example, tear or otherwise damage the cam in the lock device.
Therefore, there is a need for a spindle that may be easily adapted for use in conjunction with various separation distances between the dial and lock device as well as at various hands of installation.